Abstract:

A method and apparatus for generating a performance indicator in a
high-speed communication system. A plurality of disparate communication
status signals with differing formats from a transceiver are combined in
a logic module to create a single link quality indicator signal. The link
quality indicator signal is used to encode different operational states
of the transceiver from fully operational, to marginally operational, to
failed. The link quality indicator signal is advantageously employed to
drive a LED creating a visual performance indicator.

Claims:

1. A method of providing link quality indicator signals for a
communication system having a transceiver, the method
comprising:receiving a set of communication status signals from the
transceiver;generating a first aperiodic link quality indicator signal if
the set of communication status signals indicates an operational network
channel; andgenerating a second aperiodic link quality indicator signal
if the set of communication status signals indicates an inoperative
network channel.

2. (canceled)

3. The method of claim 1, further including:receiving a second set of
communication status signals from the transceiver;generating a periodic
link quality indicator signal if the second set of communication status
signals indicate a marginally operational network channel.

4. The method of claim 3, wherein generating a periodic link quality
indicator signal further includes determining a period of the periodic
link quality indicator signal based on the second set of communication
status signals.

5. The method of claim 3, wherein generating a periodic link quality
indicator signal further includes generating a periodic link quality
indicator signal with asymmetric high and low periods.

6-7. (canceled)

8. An apparatus for generating a link quality indicator signal for a
communication system having a transceiver, the apparatus comprising:a
quality indicator signal generator including quality indicator
logicoperable to receive a set of communication status signals from
thetransceiver, the quality indicator logic being operable to generate a
first aperiodic link quality indicator signal if the set of communication
status signals indicates an operational network channel, the quality
indicator logic being further operable to generate a second aperiodic
link quality indicator signal if the set of communication status signals
indicates an inoperative network channel.

9. (canceled)

10. The apparatus of claim 8, further comprising a light emitting diode
operably coupled to the link quality signal generator.

11. The apparatus of claim 8, the quality indicator logicbeing operable
receive a second set of communication status signals from the transceiver
and to generate a periodic link quality indicator signal if the second
set of communication status signals indicate a marginally operational
network channel.

12. The apparatus of claim 11, wherein the quality indicator logic is
operable to determine a period of the periodic link quality indicator
signal based on the second set of communication status signals.

13. The apparatus of claim 11, wherein the quality indicator logic is
operable to generate a periodic link quality indicator signal with
asymmetric high and low periods.

14. A method of providing a link quality indicator signal for a
communication system having a local transceiver, the method
comprising:generating a first aperiodic link quality indicator signal
indicating an inoperative network channel; andgenerating a second
aperiodic link quality indicator signal if an auto-negotiation complete
status signal, a link status signal and a local receiver status signal
indicate an operational network channel.

15. The method of claim 14, wherein the generation of a link quality
indicator further includes generating a periodic link quality indicator
signal if a receive error status signal indicates a marginally
operational network channel.

16. The method of claim 14, wherein the generation of a link quality
indicator further includes generating a periodic link quality indicator
signal if a mean square error status signal indicates a marginally
operational network channel.

17. The method of claim 14, wherein the generation of a link quality
indicator further includes generating a first periodic link quality
indicator signal if a receive error status signal indicates a marginally
operational network channel.

18. The method of claim 17, wherein the generation of a link quality
indicator further includes generating a second periodic link quality
indicator signal if a mean square error status signal indicates a
marginally operational network channel.

[0002]This invention relates generally to networked systems and more
specifically to performance indicators in a high-speed communication
system.

[0003]High-speed network devices within high-speed communication systems
may employ disparate communication modules with each communication module
handling a separate function for the high-speed communications device.
Each communication module may generate a variety of status signals
related to the communication module's internal processes. These status
signals may relate to the quality of the communication link established
by the high-speed communications device. For example, a communication
module may have an internal process for handling an auto-negotiation
process, such as the auto-negotiation process defined in the well known
IEEE 802.3 network standard as employed by Broadcom Inc.'s BCM5400
100/1000BASE-T Gigabit Ethernet Transceiver, in which case the
communication module may provide status signals indicating the progress
of the auto-negotiation process.

[0004]A high-speed communications device may comprise a number of
communication modules with each module generating its own status signals.
The format of the status signals may vary in characteristics dependent on
the nature of a variable value encoded within the status signal. For
example, some of the signals may be binary in nature, indicating either
total failure or normal operation, while other signals may encode
quantitative information, such as number of communication errors per unit
of time.

[0005]Each communication module may generate its own status signals
indicating that the communication module is functioning normally
independently of a communication module that may be experiencing
processing errors. In this case, monitoring a single, status signal or a
set of status signals from a communication module may not indicate the
quality of the communication link established by the high-speed
communications device.

[0006]Therefore, a need exists for a method for generating a high-speed
communication system performance signal incorporating a variety of
communication status signals. The present invention meets such need.

SUMMARY OF THE INVENTION

[0007]In one aspect of the current invention, an apparatus comprising a
quality indicator logic module receives a set of communication status
signals from a transceiver in a high-speed communications network. The
quality indicator logic module generates a link quality indicator signal
based on the set of communication status signals.

[0008]In another aspect of the current invention, the link quality
indicator signal is used to drive a Light Emitting Diode (LED) creating a
visual display.

[0009]In another aspect of the invention, a quality indicator process is
provided for generating a link quality indicator signal using an
auto-negotiation status signal, a link status signal, a local receiver
status signal, a receive error status signal, and a MSE communication
status signal.

[0011]The quality indicator process then sets the link quality indicator
signal to a second signal level if the auto-negotiation complete status
signal indicates a local transceiver auto-negotiation process is
complete. If the auto-negotiation process is not complete, the quality
indicator process sets the link quality indicator signal to the first
signal level and continues processing by checking the auto-negotiation
complete status signal again.

[0012]The quality indicator process checks the link status signal and
returns to checking the auto-negotiation complete status signal if the
link status signal indicates that a network channel has not been
established.

[0013]The quality indicator process checks the local receiver
communication status signal and sets the link quality indicator signal at
the first signal level and continues checking the link status if a local
receiver status signal indicates that the local transceiver is not
functional.

[0014]The quality indicator process then sets the link quality indicator
signal at the second signal level if the local receiver status signal
indicates that the local transceiver is functional.

[0015]The quality indicator process then sets the link quality indicator
signal at the first signal level for a first period of time and then sets
the link quality indicator signal at the second signal level for the same
period of time if a receive error status signal indicates that the local
transceiver has a reception error.

[0016]The quality indicator process sets the link quality indicator signal
at the first signal level for a second period of time and sets the link
quality indicator signal at the second signal level for the same period
of time if the MSE status signal indicates that a MSE of the local
transceiver exceeds a SNR threshold status signal level.

[0018]These and other features, aspects, and advantages of the present
invention will become better understood with regard to the following
description and accompanying drawings wherein:

[0019]FIG. 1 is a block diagram depicting an embodiment of a performance
indicator according to the present invention;

[0020]FIG. 2 is a block diagram depicting an LED embodiment of a
performance indicator according to the present invention; and

[0021]FIG. 3 is a process flow diagram of an embodiment of a performance
indicator according to the present invention.

DETAILED DESCRIPTION OF THE INVENTION

[0022]FIG. 1 is a block diagram depicting an embodiment of a performance
indicator according to the present invention. A local network chip 10 is
operably coupled through a computer network 30 to a remote network device
20 resulting in a high speed communication system 22. The local network
chip and the remote network device communicate with each other over the
network using the known IEEE 802.3 networking standard creating a network
channel 32 through the network. A single performance indicator signal,
herein termed a link quality indicator signal, 40 is generated by the
local network chip to indicate the quality of the network channel. In
operation, the local network chip monitors the quality of the network
channel and changes the level of the link quality indicator signal based
on the quality of the network channel.

[0023]The local network chip includes a local transceiver 50 operably
coupled via a plurality of network channel status signals 53 to a quality
indicator logic module 60. The quality indicator logic module includes an
encoded process 62 for receiving the plurality of network channel status
signals transmitted by the local transceiver and processing the plurality
of received network channel status signals to generate a single link
quality indicator signal. The quality indicator logic module 60 generates
a link quality indicator signal including a plurality of possible timing
sequences 70. Each of the timing sequences encodes a different aspect of
the quality of the network channel.

[0024]In one embodiment of a link quality indicator according to the
present invention, aperiodic link quality indicator signals are generated
to indicate either that the network link is fully operational or that the
network link has completely failed.

[0025]In another embodiment of a link quality indicator according to the
present invention, a plurality of periodic link quality indicator signals
are generated with the period of the generated link quality indicator
signal indicating a different problem within the local network chip's
communication modules.

[0026]The local transceiver includes a plurality of operably coupled
communication modules 52 that generate and control signals used to
establish the network channel. The communication modules generate status
signals including the plurality of network channel status signals
transmitted by the local transceiver to the quality indicator logic
module. These network channel status signals are generated according to
the known IEEE 802.3 networking standard. The network channel status
signals may or may not share the same format. For example, some of the
signals may be binary in nature, indicating either total failure or
normal operation, while other signals may encode quantitative
information, such as number of errors per unit of time.

[0027]In an embodiment of a local network chip according to the present
invention, the local transceiver includes communication modules 52. The
communication modules include higher level logic for controlling the
transceiver operations as well as signal processing circuitry and signal
processing logic responsive to the higher level logic (for example, the
PHY module) for controlling the operations of the signal processing
circuitry.

[0028]The communication modules further include logic for auto-negotiation
of a master/slave relationship according to the IEEE 802.3 standard. The
communication modules generate an auto-negotiation complete signal 76
(for example, the flp_link_good signal as defined in the IEEE 802.3
standard) indicating that the communication modules have completed an
attempted auto-negotiation with the remote network device according to
the IEEE 802.3 standard.

[0029]Even though the auto-negotiation sequence is completed, the link may
not have been established. The communication modules include logic for
generating a link status signal 76 according to the IEEE 802.3 networking
standard at the end of the auto-negotiation sequence indicating whether
or not a network link has been properly established.

[0030]The communication modules further include logic for generating a
Signal to Noise Ratio (SNR) threshold value signal 78 that correlates
with the a maximum Bit Error Rate (BER) as provided for in the IEEE 802.3
networking standard. The SNR threshold is programmable by an external
control program (not shown) thus facilitating the integration of the
local network chip in a larger network device.

[0031]In an embodiment of a quality indicator according to the present
invention, the SNR threshold is set slightly higher than the SNR
threshold called for in the IEEE 802.3 networking standard.

[0032]The communication modules generate a local receiver status signal 80
as provided for in the IEEE 802.3 networking standard. The local receiver
status signal depends on a SNR as determined by the signal processing
circuitry and on the state of a descrambler circuit included in the
signal processing circuitry. If the SNR is low and the descrambler
circuit can no longer decode the received signals, the signal processing
logic sets the local receiver status signal to indicate that data can no
longer be sent reliably over the network channel.

[0033]The communication modules further include control logic for
generating a MSE signal 82 proportional to the Mean Square Error (MSE)
produced by the signal processing circuitry. The MSE signal correlates
with the SNR of the signal processing circuitry.

[0034]The s communication modules further include control logic for
generating a receive error signal 84. The receive error signal is a
combination of a false carrier sense signal as provided for in the IEEE
802.3 networking standard and a receive coding error as provided for in
the IEEE 802.3 networking standard. The false carrier sense signal
indicates if the local transceiver receives a frame that does not conform
to the IEEE 802.3 networking standard. The receive coding error signal
indicates if a frame contains a packet with an error such as a premature
packet end as provided for in the IEEE 802.3 networking standard.

[0035]The quality indicator logic receives a clocking signal 72 from the
local network chip's timing circuit. The clocking signal is used to
provide timing information for the quality indicator logic module to
generate a plurality of link quality indicator signals with various
timing characteristics.

[0036]The quality indicator logic module receives the previously described
network channel status signals and generates a single link quality
indicator signal including a plurality of possible timing sequences 70.
Each of the timing sequences encodes a different aspect of the quality of
the network channel.

[0037]If the quality indicator logic module determines that the network
link is functioning normally, the link quality indicator signal is driven
low and remains low as long as the network link is functioning normally
86. This creates a first aperiodic link quality indicator signal
indicating that the network link is fully operational.

[0038]If the local network chip is unable to establish and maintain a
network channel with the remote network device, then the link quality
indicator signal is driven high 88 and it remains in that state until the
local network chip can reestablish the network channel. This creates a
second aperiodic link quality indicator signal indicating that the
network link is not operational at all.

[0039]If the local network chip detects a false carrier sense signal or a
receive coding error signal, the link quality indicator signal is driven
high then low at a low frequency 92. This creates a first periodic link
quality indicator signal indicating that the network link is marginally
operational because there are framing or receive coding errors.

[0040]If the local network chip detects that the MSE is greater than the
SNR threshold value, then the link quality indicator signal is driven
high then low at a high frequency 92. This creates a second periodic link
quality indicator signal indicating that the network link is marginally
operational because the MSE is higher than the SNR threshold value.

[0041]FIG. 2 is a block diagram depicting a embodiment of a quality
indicator employing a Light Emitting Diode (LED) to generate a visual
quality indicator according to the present invention. A quality indicator
LED 200 is operably coupled to a previously described link quality
indicator signal 40 and a voltage source 202. The link quality indicator
signal is driven low and the LED is energized as soon as auto-negotiation
is complete and the local network chip 10 is attempting to establish a
network channel 32 (FIG. 1). After a network channel is established, the
quality indicator LED will remain energized while the network channel is
operating reliably with a good SNR.

[0042]The link quality indicator signal will be driven high and the
quality indicator LED will no longer be energized when the local network
chip receive error signal indicates a problem with the communication
channel and the local network chip is unable to receive packet data. The
quality indicator LED will blink with a varying frequency to indicate
intermediate levels of reliability of the network channel.

[0043]The following table summarizes the operation of the quality
indicator LED:

[0044]FIG. 3 is a process flow diagram of quality indicator process of an
embodiment of a performance indicator according to the present invention.
A quality indicator logic module 60 (FIG. 1) includes an encoded quality
indicator process 62 for receiving a plurality of network channel status
signals 53 (FIG. 1) transmitted by a local transceiver 50 (FIG. 1) and
processing the plurality of received network channel status signals to
produce a single link quality indicator signal 40 (FIG. 2) used to drive
a link quality indicator LED 200 (FIG. 2).

[0045]At reset 300, the quality indicator process turns a link quality
indicator LED 200 (FIG. 2) off 302. The quality indicator process checks
a auto-negotiation complete status signal 74 (FIG. 1) and loops back to
reset the link quality indicator LED to off if the auto-negotiation
complete signal indicates that the auto-negotiation process has not been
completed.

[0046]If the auto-negotiation complete status signal indicates that the
auto-negotiation process is complete, then the quality indicator process
turns the link quality indicator LED on 308.

[0047]The quality indicator process checks 310 a link status signal 76
(FIG. 1) and returns to check the auto-negotiation complete status signal
304 if the link status signal indicates that the communication channel is
no longer established. If the auto-negotiation complete status signal
indicates that the auto-negotiation process is not complete, the quality
indicator process turns the link quality indicator LED off 302 and
continues monitoring the auto-negotiation complete status signal as
previously described waiting for the auto-negotiation complete status
signal to indicate that the auto-negotiation process is complete.

[0048]If the quality indicator process confirms that the communication
channel is open 310, the quality indicator process checks to see of a
local receiver status 80 (FIG. 1) indicates that data can no longer be
sent reliably over the network channel. If data can no longer be sent
reliably over the network channel, the quality indicator process turns
the link quality indicator LED off 314 and returns to monitoring the link
status signal 310 as previously described.

[0049]If local receive status signal indicates that data is being reliably
sent over the network channel, the quality indicator process turns the
link quality indicator LED on 316 and checks a receive error status
signal 84 (FIG. 1) to confirm that there are no framing or receive coding
errors as provided for in the IEEE 802.3 networking standard.

[0050]If the receive error status signal indicates that there are no
framing or receive coding errors, the quality indicator process turns the
link quality indicator LED off for a first period of time 320 and then
back on 322 for the first period of time. The quality indicator process
continues processing by returning to checking the link status signal 310.

[0051]In one embodiment of a quality indicator process according to the
present invention, the link quality indicator LED is turned OFF for a
period of 80 msec and back on for a period of 80 msec in order to cause
the link quality indicator LED to blink at a low frequency if the
auto-negotiation is complete and the network link is established but
there are framing or receive coding errors.

[0052]In another embodiment of a quality indicator process according to
the present invention, the on and off periods of the LED are different
creating a periodic signal with asymmetric on and off periods.

[0053]If the receive error signal indicates that there are no framing or
receive coding errors as provided for in the IEEE 802.3 networking
standard, the quality indicator process checks a previously described MSE
signal 82 (FIG. 1) by comparing 324 the MSE signal to a previously
described SNR threshold signal 78 (FIG. 1). If the MSE signal is less
than or equal to the SNR threshold signal, the quality indicator process
continues processing by checking 310 the link status signal as previously
described.

[0054]If the MSE signal is greater than the SNR threshold signal, the
quality indicator process turns the link quality indicator LED off for a
second period of time 326 and then back on 327 for the same period of
time. The quality indicator process continues processing by returning to
checking the link status signal 310.

[0055]In one embodiment of a quality indicator process according to the
present invention, the link quality indicator LED is turned OFF for a
period of 3 msec and back on for a period of 3 msec in order to cause the
link quality indicator LED to blink at a high frequency.

[0056]In another embodiment of a quality indicator process according to
the present invention, the on and off periods of the LED are different
creating a periodic signal with asymmetric on and off periods.

[0057]Although this invention has been described in certain specific
embodiments, many additional modifications and variations would be
apparent to those skilled in the art. It is therefore to be understood
that this invention may be practiced otherwise than as specifically
described. Thus, the present embodiments of the invention should be
considered in all respects as illustrative and not restrictive, the scope
of the invention to be determined by claims supported by this application
and the claim's equivalents rather than the foregoing description.